DEARBORN, Mich. — Ford Motor Co. will fall short of its goal of producing 250,000 hybrid vehicles a year by 2010, chief executive Bill Ford says.

The company's top executive announced the goal in September. He said then that gas-electric hybrid engines would be available in half the Ford, Lincoln and Mercury lineup by 2010.

The goal of 250,000 hybrids a year would have been 10 times the number that Ford was building at the time.

In an e-mail message to employees Wednesday, he said the company instead would focus on other alternative fuels, according to The Detroit News and the Detroit Free Press.

"What I didn't foresee at the time was how rapidly other technologies would evolve," he wrote. "Now, I am convinced that the objective we had set earlier to build capacity for 250,000 hybrids at the end of the decade is too narrow to achieve our larger goals of substantially improving fuel economy and CO2 performance."

Sierra Club upsetDan Becker, head of the Sierra Club's global warming program, said the environmental group was "appalled" by Ford's shift.

"Ford is rapidly becoming the automaker that cried wolf," he said in a statement Thursday. "In 2000, Ford promised to increase the fuel economy of its SUVs by 25 percent over five years; it walked away from that promise in 2003.

"By swapping out more clean and efficient hybrids for more flex-fuel vehicles, Ford is engaging in a classic bait and switch," Becker added. "Even the Bush administration admits that flex fuels run on regular gasoline 99 percent of the time, since E85 is only available at an infinitesimal .003 percent of the nation’s gas stations."

Big 3 to double flex-fuel carsWord of Ford's shortfall on hybrid vehicles came on the same day that Bill Ford and the heads of General Motors Corp. and DaimlerChrysler AG's Chrysler Group said they would double production of flexible-fuel vehicles by 2010.

Flexible-fuel vehicles include ones capable of running on ethanol-gasoline blends and other biofuels.

Ford now plans to make 500,000 flexible-fuel vehicles per year by 2010. It had not previously stated a target for flexible-fuel vehicles but had internally expected to make about 250,000 a year by 2010, the Wall Street Journal reported Wednesday.

Hybrid vehicles are powered by a combination of internal combustion engines and electrical batteries, which are charged when the vehicles brake.

Ford now sells Ford Escape and Mercury Mariner hybrid sport utility vehicles. It says it plans to introduce hybrid versions of the Mazda Tribute SUV in 2007 and the Ford Fusion and Mercury Milan sedans in 2008.